Review of GI Anatomy I

Question 1

The elimination of insoluble substances and other materials occurs in the

Answer 1

Large intestine

Question 2

After the oral cavity, the digestive system consists of which 4 layers?

Answer 2

1. ) Mucosa
2. ) Submucosa
3. ) Muscularis Externa
4. ) Serosa/adventitia

Question 3

Epithelium of the mucosal layer lines the lumen of the digestive tract and originates from ENDODERM for

Answer 3

Forgut, midgut, and hindgut derivatives (pharynx to large intestine)

Question 4

The things that are derived from ectoderm are derivatives of the

Answer 4

Stomodeum and proctodeum (mouth and lower anal canal)

Question 5

Forms from invagination of the developing gut epithelium and intramural-extramural glands extend through the gut layers with ducts that carry secretions to the luminal surface

Answer 5

Glandular Epithelium

Question 6

Surrounds the endoderm and forms connective tissue, muscle, and serosa of the digestive viscera

Answer 6

Mesoderm

Question 7

Neural crest cells migrate into the gut to form the

Answer 7

Enteric ganglia

Question 8

By week 4, the primordial gut is made up of endoderm-lined

Answer 8

Foregut, midgut, and hindgut

Question 9

Forms epithelium of the pharynx, esophagus, stomach, proximal duodenum and liver, gall bladder, pancreas with associated duct systems

Answer 9

Foregut endoderm

Question 10

Forms epithelium of the distal duodenum, jejunum, ileum, cecum, appendix, ascending colon, proximal ⅔ transverse colon

Answer 10

Midgut endoderm

Question 11

The midgut is initially connected to the yolk sac via the

Answer 11

Vitteline Duct

Question 12

Forms epithelium of the distal ⅓ transverse colon, descending colon, sigmoid colon, rectum, proximal part of anal canal

Answer 12

Hindgut endoderm

Question 13

The ectoderm-endoderm membranes of the stomodeum and foregut form the

Answer 13

Oropharyngeal/buccopharyngeal membrane

Question 14

A birth defect in which the gut structures remain herniated at the umbilicus because of failure of intestines to return back to abdominal cavity during development

Answer 14

Omphalocele

Question 15

In omphalocele, are the intestines in contact with the amniotic fluid?

Answer 15

No

Question 16

Early in development, the embryonic body cavity (intraembryonic coelom) is lined with

Answer 16

Mesoderm

Question 17

Divides into visceral and parietal mesoderm with an intervening body cavity

Answer 17

Lateral Plate mesoderm

Question 18

Thus, the body cavity in the abdominopelvic region is the

Answer 18

Peritoneal cavity

Question 19

Organs that protrude into the peritoneal cavity only slightly are

-Example: kidneys

Answer 19

Retroperitoneal

Question 20

Others such as the stomach and spleen protrude completely and are

Answer 20

Intraperitoneal

Question 21

Intraperitoneal organs are connected to the posterior abdominal wall by a

Answer 21

Mesentery

Question 22

Between the thoracic diaphragm superiorly, pelvic diaphragm inferiorly, abdominal wall anterolaterally, vertebral column-muscles posteriorly

Answer 22

Abdominopelvic cavity

Question 23

A serosa/serous membrane that covers intraperitoneal organs and peritoneal walls

Answer 23

Peritoneum

Question 24

Consists of mesothelium (simple squamous epithelium) with a thin layer of supportive loose connective tissue

Answer 24

Serosa

Question 25

Continuity between parietal and visceral peritoneum occurs in

Answer 25

Mesentery

Question 26

Double-layered peritoneal membranes that form from continuity between parietal and visceral peritonea passing between the posterior body wall and the viscera

Answer 26

Mesenteries

Question 27

The hepatoduodenual ligament is a double layer of peritoneum at the free edge of the lesser omentum that connects duodenum to liver. It conducts the

Answer 27

Portal triad (hepatic portal vein, proper hepatic artery, common bile duct)

Question 28

The parietal peritoneum is supplied by the same neurovasculature as the overlying body wall and is thus sensitive to

Answer 28

Pressure, pain, heat, cold, and laceration

Question 29

Somatic pain from the parietal peritoneum is generally

Answer 29

Well localized

Question 30

Patients experience more pain with large incisions of the well-innervated parietal peritoneum. Small laparoscopic incisions reduce pain and potential for contamination and

Answer 30

Peritonitis

Question 31

Insensitive to touch, heat, cold, and laceration

Answer 31

Visceral peritoneum

Question 32

Poorly localized visceral pain from the visceral peritoneum is activated by stretching and chemical irritation and is referred to

Answer 32

Dermatomes

Question 33

Where is pain from the foregut, midgut, and hindgut typically located?

Answer 33

1. ) Foregut = epigastric 2. ) Midgut = umbilical 3. ) Hindgut = hypogastric

Question 34

Include stomach, liver, gall bladder, spleen, tail of pancreas, beginning of duodenum, jejunum, ileum, cecum, appendix, transverse colon, sigmoid colon

Answer 34

Intraperitoneal organs

Question 35

Include most of duodenum, ascending colon, descending colon, most of pancreas, upper rectum

Answer 35

Secondarily retroperitoneal organs

Question 36

Include kidney, adrenal gland, ureter, aorta, IVC, lower rectum, anal canal

Answer 36

Primary retroperitoneal organs

Question 37

Inflamed peritoneum (from surgery or infection) can lead to surfaces that are sticky with

Answer 37

Fibrin

Question 38

During healing, fibrous scar tissue can form abnormal attachments between visceral and parietal serosal layers, known as

Answer 38

Adhesions

Question 39

This tethering may cause chronic pain or emergency complications such as

Answer 39

Intestinal obstruction

Question 40

The arterial supply to the structures of the oral cavity, pharynx, and upper esophagus are from

Answer 40

Branches of external carotid and subclavian arteries, and the thoracic aorta

Question 41

Venous drainage from the structures of the oral cavity, pharynx, and upper esophagus is from tributaries to the

Answer 41

Subclavian vein, azygous vein, SVC, and IVC

Question 42

Branches of the abdominal aorta include the

Answer 42

Celiac trunk, SMA, and IMA

Question 43

Supplies derivatives of the foregut in the abdominopelvic cavity

Answer 43

Celiac trunk

Question 44

Supplies the midgut

Answer 44

Superior Mesenteric Artery (SMA)

Question 45

Supplies derivatives of the hindgut and abdominopelvic cavity

Answer 45

Inferior Mesenteric Artery (IMA)

Question 46

Anastomoses between these branches occur through the

Answer 46

Marginal Artery

Question 47

May help demonstrate obstruction of branches, which can result in ischemia and necrosis (tissue death)

Answer 47

An arteriogram

Question 48

The necrotic segment may become non-functional. This will result in colicky pain as well as

Answer 48

Abdominal distinction, vomiting, fever, and dehydration

Question 49

Much of the gut drains into the hepatic portal vein via the

Answer 49

Splenic vein, SMV, and IMV

Question 50

The hepatic portal vein is flanked by capillary beds, with one capillary bed in the gut and the other in the

Answer 50

Liver (as sinusoids)

Question 51

Anterior to the IVC and posterior to the neck of the pancreas

Answer 51

Hepatic portal vein

Question 52

The hepatic protal vein is formed by the union of the

Answer 52

SMV and splenic vein

Question 53

Drains into splenic vein (60%) or juncture of splenic vein with SMV (40%)

Answer 53

IMV

Question 54

Blood entering the hepatic portal veins contains products of RBC breakdown from the spleen and absorbed nutrients from

Answer 54

Intestines

Question 55

Portal-systemic anastomoses, in which the portal venous system communicates with the systemic venous system, can be seen in the submucosa of the

Answer 55

Inferior esophagus, peri-umbilical region, and inferior anal canal

Question 56

Portal circulation through the liver can be impeded because of cirrhotic liver disease that causes

Answer 56

Portal hypertension

Question 57

The collateral circulation seen in portal hypertension is possible because the hepatic portal vein and its tributaries lack

Answer 57

Valves

Question 58

However, the excess blood volume in the collateral venous routes may lead to potentially fatal

Answer 58

Hemorrhage

Question 59

Presynaptic sympathetic fibers in the greater, lesser, least, lumbar splanchnic nerves synapse on postsynaptic sympathetic prevertebral ganglia associated with branches of the

Answer 59

Abdominal Aorta

Question 60

Postsynaptic sympathetic axons and presynaptic parasympathetic axons make up the

Answer 60

Periarterial plexuses

Question 61

Periarterial plexuses that travel along branches of the celiac trunk, SMA, IMA to provide autonomic innervation to smooth muscles and glands of the

Answer 61

Foregut (celiac), midgut (SMA)., and hindgut (IMA)

Question 62

The submucosal plexus of Meisser and myenteric plexus of Auerbach are located within the gut wall layers and receive stimulatory input from preganglionic parasympathetic axons to

Answer 62

Promote Digestion

Question 63

The submucosal plexus of Meisser and myenteric plexus of Auerbach are located within the gut wall layers and receive inhibitory input from postganglionic sympathetic axons to

Answer 63

Slow Digestion

Question 64

Thus, although the intrinsic, enteric nervous system can function independently, it is induced by the parasympathetic preganglionic fibers of the vagus and pelvic splanchnic nerves to increase

Answer 64

Smooth muscle peristalsis and glandular secretion for digestion

Question 65

Thus, although the intrinsic, enteric nervous system can function independently, it is inhibited by sympathetic postganglionic fibers whose cell bodies are located

Answer 65

Prevertebral ganglia

Question 66

Act in the digestive system to stimulate smooth muscle peristalsis and glandular secretion

Answer 66

Parasympathetics

Question 67

Act in the digestive system to inhibit digestion and induce vasoconstriction

Answer 67

Sympathetics

Question 68

Poorly localized pain

Answer 68

Visceral pain

Question 69

Visceral pain from foregut derivatives, for example, refers to the epigastric dermatomes because pain afferents accompany the sympathetic greater splanchnic nerve to reach

Answer 69

T5-T9 segments

Question 70

The MOUTH is the opening to the digestive tract and includes the

Answer 70

Lips, cheeks, teeth, gums/gingivae, tongue, and palate

Question 71

The dorsum (top surface) of the TONGUE has a

Answer 71

Sulcus terminalis and lingual papillae

Question 72

Separates the anterior body of the tongue from the posterior root

Answer 72

Sulcus terminalis

Question 73

Made up of filiform, fungiform, and circumvallate types, some of which have taste buds

Answer 73

Lingual papillae

Question 74

Sensation from the anterior 2/3 of the tongue is conveyed via

Answer 74

1. ) CNVII for taste | 2. ) CNV3 for general

Question 75

All sensation from the posterior 2/3 of the tongue is conveyed via

Answer 75

CNIX (w/ some taste from CNX also)

Question 76

Can be seen on the posterior tongue

Answer 76

Lingual tonsils

Question 77

Almost all tongue muscles are innervated by the

Answer 77

Hypoglossal nerve (CNXII)

Question 78

In adult humans, what is the make up of permanent teeth?

Answer 78

16 mandibular and 16 maxillary

Question 79

Twenty (20) deciduous teeth precede permanent teeth and are also called

Answer 79

Milk or baby teeth

Question 80

The hardest substance in the body (contains ~95% hydroxyapatite)

Answer 80

Enamel

Question 81

Tooth enamel forms by secretions from ectoderm-derived

Answer 81

Ameloblasts

Question 82

Deep to enamel, dentin forms from

Answer 82

Neural crest-derived odontoblasts

Question 83

Surrounds the soft mesenchyme-like tooth pulp that contains vessels and nerves

Answer 83

Dentin

Question 84

Surrounds the outer surface of the tooth root

Answer 84

Cementum

Question 85

Passes masticated food in the form of a bolus from the mouth and pharynx through the ESOPHAGUS to the stomach

Answer 85

Peristalsis

Question 86

The portion of the diaphragm that surrounds the esophagus forms the

Answer 86

Lower/inferior esophageal sphincter

Question 87

The collapsed lumen of the empty esophagus also prevents food or stomach juices from

Answer 87

Regurgitating

Question 88

Most of the esophagus is covered by an outer adventitial layer of connective tissue except for visceral peritoneum covering the

Answer 88

Abdominal esophagus

Question 89

The squamocolumnar juncture where the esophageal mucosa changes to gastric mucosa

Answer 89

Z-line

Question 90

Immediately superior to the Z-line

Answer 90

Lower esophageal sphincter

Question 91

If gastric acid reflux from the stomach to the esophagus occurs, abnormal metaplasia (change in epithelial type) may occur in the esophagus and result in

Answer 91

Chronic inflammation (reflux esophagitis), ulceration, or difficulty swallowing (dysphagia)

Question 92

Weakening of the diaphragmatic musculature that forms the lower/inferior esophageal sphincter may be seen in middle age (incidence increases with age) and can lead to widening of the esophageal hiatus and even

Answer 92

Hiatal hernia

Question 93

In a hiatal hernia, a portion of the stomach moves through the esophageal hiatus into the

Answer 93

Posterior mediastinum of the thoracic cavity

Question 94

Over 95% of hiatal hernias are

Answer 94

Type 1 (sliding type) hernias

Question 95

The abdominal part of esophagus and the cardiac-fundus parts of the stomach slide through hiatus into thorax in a

Answer 95

Sliding type hernia

Question 96

Because of its course through the neck, thorax, and abdomen, multiple arteries supply the esophagus, including branches of the

Answer 96

External Carotid, subclavian, and thoracic-abdominal aorta

Question 97

Can occur as a result of portal hypertension

Answer 97

Submucosal esophageal varices

Question 98

Causes a reversal of blood flow in the valveless esophageal veins so that there is increased blood volume in the dilating submucosal esophageal veins and tributaries to the systemic venous circulation

Answer 98

Portal hypertension due to liver cirrhosis

Question 99

For larger meals, gastric rugae (mucosal-submucosal folds) distend and can expand to hold

Answer 99

2-3L of food

Question 100

The microscopic glands within the stomach mucosa are tubular in shape with branching at the deeper/lower ends. The branched ends are

Answer 100

Gastric glands